Incomplete surface treatment

01 Concrete bonding surface is not polished in place

The polishing of the concrete bonding surface will lead to the reduction of the bonding strength between the steel plate and the concrete, which is easy to appear void in the later stage, and needs to be reworked.

The concrete bonding surface shall be polished to the exposed solid concrete structure layer, and the surface scum and dust shall be blown off with compressed air. The bonding surface shall also be wiped clean before pasting.

02 High moisture content of base surface

The high moisture content of concrete will affect the curing and strength of epoxy adhesive, resulting in the decrease of its bonding strength with concrete surface. For the concrete with high moisture content, manual drying treatment shall be carried out or Guterbond moisture curing steel adhesive shall be selected.

03 Base surface defects not repaired

The defects on the concrete surface will cause the epoxy adhesive to be filled insufficiently and form hollowing, resulting in insufficient effective bonding area between the steel plate and the concrete, thus affecting the bonding strength.

Small defects, such as honeycomb and pockmarked surface, can be repaired with Gutebang concrete epoxy repair adhesive, and large defects can be repaired with Gutebang epoxy mortar or polymer mortar, and the repair materials can be polished and leveled after hardening.

The preparation of epoxy adhesive is not standard

01 Do not weigh, use agents A and B according to your feeling

When preparing steel adhesive, use electronic scale to accurately weigh agents A and B to prevent low curing strength, uncontrollable curing speed, and partial or overall non-curing. At the same time, the Technical Code for Safety Appraisal of Engineering Structural Reinforcement Materials (GB 50728-2011) stipulates that the structural adhesive with changed proportion is regarded as the adhesive without safety appraisal.

02 Increase the dosage of agent B (curing agent) arbitrarily

When it is necessary to improve the curing rate, the products can be customized from the material manufacturer Goodbond, and the dosage of agent B cannot be increased without authorization. Increasing the blending ratio can not improve the curing rate, but may affect the material properties.

03 Add other components such as quartz sand or diluent at will

Adding quartz sand or diluent and other components to the steel adhesive will change the proportion, properties, density, mechanical properties, etc. of the adhesive. According to the provisions of the Technical Code for Safety Appraisal of Engineering Structural Reinforcement Materials (GB 50728-2011), changing the composition of the structural adhesive will be considered as not conducting safety appraisal.

04 Mixing and mixing at will

Components A and B of epoxy colloid shall be fully mixed evenly. It is recommended to use mechanical mixing to evenly mix, and it can be mixed evenly at low speed through a hand-held mixer.

05 Mismatch between single mixing amount and construction speed

The larger the volume of the prepared steel adhesive, the more it will accumulate, the less easily the heat of the glue liquid (colloid) will be emitted, and the shorter the operational time will be. Therefore, glue mixing and construction can be carried out according to the actual situation of the site, and a small number of glue mixing methods can be adopted as far as possible for preparation and construction.

Anti-corrosion treatment is not in place

The outer surface of the steel plate should also be treated to remove rust and dirt, so as not to affect the bonding strength of the anti-corrosion material and the steel plate.

"Three materials, seven construction", the construction process has a great impact on the quality of carbon fiber reinforcement, and special attention should be paid to these problems in the process.